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2 Sheets-Sheet 1.

(No Model.)

S. J. MILES.

GRATE FOR BURNING HARD GOAL sLAoK.

No. 454,490. Patented June 23,1891.

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S. J. MILES. GRATE FOR BURNING HARD GOAL SLACK. No. 454,490. Patented June 23,1891.

naw/mm m 351 A; Gil iam W1 MOW UNITED STATES PATENT OFFICE.

SAMUEL J. MILES, OF CHICAGO, ILLINOIS, ASSIGNOR TO FERDINAND SIEGEL, OF SAME PLACE.

GRATE FOR BURNING HARD-COAL SLACK.

SPECIFICATION forming part of Letters Patent No. 454,490, dated June 23, 1891.

' Application filed October 23, 1889. Serial No. 327,921. (No model.)

To all whom it may concern.-

Be it known that I, SAMUEL J. MILES, a citizen of theUnited States,andaresidentof Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Grates for Burning Hard- Ooal Slack and the Like, of which the following is a specification.

My invention relates to grate-bars and attachments designed especially for burning hard-coal screenings and the like. It isillus- 'trated in the accompanying drawings, whereiii- Figure 1 is a side view of a portion of the boiler and fire-box. Fig. 2 is a plan view of the grate-bars in position. Fig. 3 is a front view with the front portion of the fire-box removed. Fig. 4 is a longitudinal section of one bar, and Fig. 5 a cross-section of the same.

Like parts are indicated by the same letter in all the figures.

A is a boiler; B, a fire-box; C, the sides thereof.

D is the bridge-wall.

E E are the hollow grate-bars placed longitudinally in the fire-box and supported on the ledges E E.

F F are ledges within such grate-bars, upon which rest the perforated lids G G, the same being in sections, if desired, as shown in Fig. 2, and perforated by the apertures H H, as indicated, or by the slots H H as also indicated.

J J are pipes leading each from the distributing-box K to one of the grate-bars E E.

E E are transverse partitions in the gratebars, whereby they are divided into sections and greatly strengthened, and into each one of such sections opens one of the pipes J.

E E are nipples on the grate-bars, by means of which the pipes J are connected thereto.

L is a pipe leading from the fan N to the distributing-box K.

M is a door in one end of such distributingbox, by means of which it may be cleaned.

O is a slide moving along between the ledges P P in the side of the gratebars E E and perforated at R R, so as, when desired, to uncover the perforations S S in the side of the grate-bar and permit of a natural draft in the event of the forced draft not being used.

The use and operation of my invention are as follows: The fan N being in operationya current of cold air, or, if desired, of hot air, taken from a suitable source, is directed with any desired velocity through pipe L into the distributing-box K. Thence it passes through the various pipes J J into the hollow gratebars E E. From these bars it passes upward through the holes H II in the covers G and through the slack-coal distributed over the surface of such bars. By this means this slack is kept loose and is sufficiently mingled with the air to permit of its combustion. Should any of the dust or slack or particles of coal drop backward through the apertures H H in the covers, it will pass down from such grate-bars through the inclined pipes J, thence to the distributer K, in the bottom of which it would accumulate. From this distributer it can be easily removed by opening the door K and drawing or pulling it out by hand or forcingit out by an air-current. By this means the clogging of the grate-bars and air-pipes is prevented. hen the blast of air is forced up through the pipes J coming from the distributing-box K, it will supply a suificient draft to support combustion in the fire-box; but if for any reason this means of furnishing a draft should be dispensed with by moving the slide and uncovering the apertures in the side of the gratebarsa sufiicient draft can be furnished directly through such gratebars. The transverse walls in the grate-bars strengthen them and prevent twisting, warping, and breaking. The making of the lids or top of the grate-bars in section is calculated to permit the easy and rapid removal and replacement of injured forces, and the condition of any part of the grate-bars can easily be ascertained at any time by raising one or more portions of the lids.

Any desired means for connecting the airpipes J J with the distributing-box and with the grate-bars may be employed, it only being necessary to make such connections as would permit the easy removal of the various parts.

The pipes J J may be made of any desired material, size, and shape, as experience may find necessary for any given work.

The slots or long narrow apertures in the hollow grate-bar lids are found to be specially valuable in furnaces of this character, as the small round apertures are likely to be clogged 10 is as follows:

The combination of a series of hollow gratebars with a distributing-box below the same, an air-supply pipe leading into the same, and a series of inclined air-pipes leading from such distributing-box to the hollow grate-bars. I

- SAMUEL J. MILES.

Witnesses:

FRANCIS W. PARKER, CELESTE P. CHAPMAN. 

